Till: CONCHUBLA. 6 i 
destroyed by some enemy rather than of having died from natural 
causes. As has been shown, the decrease in number is a general and 
not a local occurrence, and it takes place without regard to the 
abundance of food. These circumstances seem to point to the strong 
probability that birds are the useful agents in the reduction of the 
numbers of the adults of the conchuela. 
ARTIFICIAL CONTROL. 
Under the heading, "Artificial control," will be discussed only 
those measures which have little or no application except for the 
conchuela, together with such measures as have been the object <>{' 
especial observation during the observation of that pest. 
PREVENTIVE MEASURES. 
Clearing hind of mesquite. — As a means of obviating in a large 
measure the destruction by the conchuela, the prevention of spring 
multiplication of the pest on mesquite in the vicinity of cotton fields 
is of prime importance. Near Llano, Tex., Mr. J. C. Crawford, of 
this Bureau, on September 3, 1905, found an excellent example of 
the conditions which may result from the neglect of a breeding place 
of plant-bugs. As would be expected from its previous history else- 
where, the conchuela was in comparatively small numbers at that 
season of the year, but associated with it were two other plant-bugs, 
which will be treated later, Largus succinctus L. and Nezara hUaris 
Say. These three pests were breeding on a group of about 4 or 5 mes- 
quite, located just outside of the cotton field. In the cotton held 
the damage to the bolls and the abundance of the plant-bugs in the 
section close to the mesquite, as compared with other parts of the 
held, gave almost conclusive evidence that the presence of the trees 
mentioned was largely or entirely responsible for the conditions 
found. In this and similar cases, therefore, the removal of the mes- 
quite would unquestionably result in considerable benefit to the 
cotton, repaying the trifling cost many times over in a single season. 
Under conditions such as those at Tlahualilo, where the cotton 
and surrounding mesquite land are under the same management or 
ownership, the policy should be adopted o( removing, as fast as 
practicable, the mesquite, which experience has shown to be an ele- 
ment of danger. Where farms are comparatively small and a 
diversity of crops is grown, as at Barstow, Tex., the results might 
not be as striking as elsewhere, but concerted effort among land- 
owners toward the eradication of mesquite growing in and around 
cultivated lands is recommended. 
Prevention of excessivt multiplication on alfalfa and other plants.— 
In addition to mesquite, alfalfa is the only other (ood plant which 
has thus far shown itself likely to harbor the conchuela in numbers 
